Nobody makes what you’re looking for because when the weather gets soft, and it will it will interfere with getting a proper grip on the gun if you need to draw it in an emergency. There’s an old saying they’re carrying a gun is supposed to be comforting not comfortable. The priority is being armed and being effective when the firearm is needed.
Many will wear an undershirt even if it is just the a shirt/tank top style under their primary cover garment to place some thing between the gun and the skin.
With regard to how to carry a firearm with the least discomfort number one is it is much easier to recommend a firearm to someone then a holster, everyone is built differently and you have to try a few until you find what works for you much like shoes. The other part of the equation that is often ignored is wearing a proper belt.